Dry prosthetic heart valve packaging system

ABSTRACT

A packaging assembly for storing a bioprosthetic heart valve without a liquid preservative solution is provided. The packaging system includes a holder, a cage, a storage tray and an insert sized to provide a cap over the cavity of the storage tray. The holder comprises a shaft and an engagement structure configured for removably attaching a bioprosthetic heart valve. The cage comprises an upper end, the cage configured to at least partially enclose the bioprosthetic heart valve. The storage tray comprises a cavity for housing the cage. The insert comprises a slot having a closed central end and an open outer periphery, the shaft of the holder being non-rotatably retained at the closed central end. The insert defines a flat, generally planar disc comprising at least one of outward projections and flow passages. The packaging assembly does not comprise a liquid preservative solution.

RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 14/221,101, filed Mar. 20, 2014, which is a continuation ofU.S. patent application Ser. No. 13/039,166, filed Mar. 2, 2011 andissued as U.S. Pat. No. 8,679,404on Mar. 25, 2014which claims priorityunder 35 U.S.C. § 119(e) to U.S. Provisional Application No. 61/310,851,filed Mar. 5, 2010, the entire disclosures of which are herebyincorporated by reference in their entireties.

FIELD OF THE INVENTION

The present invention generally relates to packaging for prostheticheart valves and, more particularly, to an assembly for sterile storageof dry prosthetic heart valves.

BACKGROUND OF THE INVENTION

Heart valve disease continues to be a significant cause of morbidity andmortality, resulting from a number of ailments including rheumatic feverand birth defects. Currently, the primary treatment of aortic valvedisease is valve replacement. Worldwide, approximately 300,000 heartvalve replacement surgeries are performed annually, and about one-halfof these patients received mechanical heart valves, which are composedof rigid, synthetic materials. The remaining patients receivedbioprosthetic heart valve replacements, which utilize biologicallyderived tissues for flexible fluid occluding leaflets.

The most successful bioprosthetic materials for flexible leaflets arewhole porcine valves and separate leaflets made from bovine pericardiumstitched together to form a tri-leaflet valve. However, flexibleleaflets formed of polymeric, fiber-reinforced, and other syntheticmaterials have also been proposed. The most common flexible leafletvalve construction includes three leaflets mounted to commissure postsaround a peripheral non-expandable support structure with free edgesthat project toward an outflow direction and meet or coapt in the middleof the flowstream. A suture-permeable sewing ring is provided around theinflow end.

Bioprosthetic heart valves are conventionally packaged in jots filledwith preserving solution for shipping and storage prior to use in theoperating theater. To minimize the possibility of damage to therelatively delicate bioprosthetic heart valves, they are stabilized withbracketing structure to prevent them from striking the inside of thejar. Prior to implantation in a patient, the valve is removed from thejar and then rinsed in a shower or immersed and agitated in a bath.Prosthetic valves typically have a valve holder centrally located andsutured thereto, and the holders used for both are attached to theproximal end—to the inflow sewing ring for mitral valves and to theoutflow commissure tips for aortic valves—so that an attached surgicaldelivery handle extends proximally out of the implant site.

Glutaraldehyde is widely used as a storage solution due to its sterilantproperties but is known to contribute to calcification. Strategies tominimize glutaraldehyde content in the final product have beendemonstrated to mitigate in vivo calcification.

One such strategy is to dehydrate the bioprosthetic tissue in aglycerol/ethanol mixture, sterilize with ethylene oxide, and package thefinal product “dry.” This process circumvents the potential toxicity andcalcification effects of glutaraldehyde as a sterilant and storagesolution. There have been several methods proposed to use glycerine,alcohols, and combinations thereof as post-glutaraldehyde processingmethods so that the resulting tissue is in a “dry” state rather than awet state with excess glutaraldehyde. These approaches avoid the use ofaqueous liquid aldehyde, or liquid sterilant as storage solutions fortissue and devices. Glycerol-based methods can be used for such storage,such as described in Parker et al. (Thorax 1978 33:638). Also. U.S. Pat.No. 6,534,004 (Chen et al.) describes the storage of bioprosthetictissue in polyhydric alcohols such as glycerol.

In processes where the tissue is dehydrated in an ethanol/glycerolsolution, the tissue may be sterilized by ethylene oxide, gammairradiation, or electron beam irradiation. Ethylene oxide sterilizationrequires exposing the tissue to increased temperatures and water vaporwhich may generate oxidative damage in the tissue (Olde Damink, L. H. etal. J Biomed Mater Res 1995 29:149). Gamma Irradiation is known togenerate significant reactive oxygen species in collagenous substrateswhich causes backbone scission and breakage of collagen fibrils (Ohan, MP et. al. J Biomed Mater Res A 2003 67:1188). This damage will lead todecreased mechanical and biochemical functionality in the tissue.Electron beam irradiation will also cleave the collagen backbone andlead to deterioration of the tissue structure and reactivity (Grant, R Aet al. J Cell Sci 1970 7:387). Damage from oxidation duringsterilization and/or storage may contribute to valve deterioration andstructural failure.

U.S. Patent Publication No. 2009/0164005 to Dove, et al. presentssolutions for certain detrimental changes within dehydrated tissue thatcan occur as a result of oxidation either from sterilization,atmospheric exposure during storage and handling, or from in vivooxidation. Dove, et al. propose permanent capping of the aldehyde groupsin the tissue (reductive animation) to help prevent significantoxidation of the tissue and lead to longer service lifetimes of thematerial. The process involves chemical capping of aldehydes (and otherspecies) or otherwise neutralizing of the dehydrated tissue to preventoxidation. Dove, el al. also describe the addition of chemicals (e.g.antioxidants) to the dehydration solution (e.g., ethanol/glycerol) toprevent oxidation of the tissue during sterilization (ethylene oxide,gamma irradiation, electron beam irradiation, etc.) and storage.

In view of the development of dry tissue heart valves, opportunities foralternative packaging for such valves arise that will save money andfacilitate deployment in the operating field.

SUMMARY OF THE INVENTION

The present application discloses sterile packaging for drybioprosthetic heart valves. New tissue treatment technology allows forpackaging the tissue valves without liquid glutaraldchyde in a drypackage. A double sterile barrier package disclosed herein contains,protects and preserves the dry bioprosthesis during ETO sterilization,transit and storage.

The present application provides packaging for prosthetic heart valvesincluding art assembly for stabilizing dry prosthetic tissue implantssuch as heart valves during storage. The packaging assembly includes adouble sterile barrier that permits gas sterilization of the tissueimplant, and prevents oxidation of the implant during long-term storage.Tissue heart valves may be suspended within a cavity of an inner rigidtray and a cap may be placed over the cavity to limit movement of thevalve therein. The inner tray is placed and sealed within an outersterile barrier, such as another rigid tray or a flexible pouch. Theouter sterile barrier may include a double seal so that a firstgas-permeable seal can be closed and the contents gas sterilized, afterwhich a second gas-impermeable seal can be closed to seal out anyfurther atmospheric contact with the tissue implant. This keeps theimplant from being oxidized. In one embodiment two nesting trays areused for redundant sterile barriers, and a gas-impermeable (e.g., foil)label is placed over the outer tray to provide the gas-impermeable seal.

In accordance with one method for packaging a dry tissue implantdisclosed herein, a tray is provided having an upper surface and acavity surrounded by an upper rim and descending downward therefrom. Atechnician places a dry tissue implant in the tray cavity and secures itfrom excessive movement therein. The technician engages a cap with thetray rim and over the cavity, the cap constraining the tissue implant inthe cavity while providing gas flow passages for gas flow in and out ofthe cavity. The tray is then seated by covering the tray upper surfacewith a gas-permeable lid, and the sealed tray and tissue implant thereinare placed into a secondary container having a gas-permeable seal toform a dual barrier assembly. The dual barrier assembly is subjected togas-based sterilization; and the secondary container is scaled with agas-impermeable barrier to prevent gas transfer with the surroundingatmosphere. One way to seal the secondary container from the surroundingatmosphere comprises placing the secondary container within agas-impermeable tertiary container such as a pouch having agas-impermeable seal.

Another method disclosed herein is for packaging a dry tissue heartvalve, and comprises the steps of:

-   -   providing a primary container having a gas-permeable seal;    -   placing a dry tissue heart valve and implant holder therefore in        the primary container;    -   limiting movement of the heart valve in the primary container        while providing gas flow passages around the heart valve;    -   sealing the primary container with the gas-permeable seal;    -   placing the sealed primary container and tissue implant therein        into a secondary container and sealing the secondary container        with a gas-permeable seal to form a dual barrier assembly;    -   subjecting the dual barrier assembly to gas-based sterilization;        and    -   sealing the secondary container with a gas-impermeable barrier        to prevent gas transfer with the surrounding atmosphere.

Another method disclosed herein for packaging a dry aortic tissue heartvalve includes first providing a tray having an upper surface and acavity surrounded by an upper rim and descending downward therefrom. Atechnician secures a dry aortic tissue heart valve and implant holdertherefore to a folding clamshell. The heart valve secured to theclamshell is placed in the tray cavity. The clamshell is sited andshaped to engage the tray rim over the cavity and limit verticalmovement of the heart valve in the cavity while providing gas flowpassages for gas flow in and out of the cavity. The tray is then scaledby covering the tray upper surface with a gas-permeable lid, and placedinto a secondary container having a gas-permeable seal to form a dualbarrier assembly. A technician subjects the dual barrier assembly togas-based sterilization, and then seals the secondary container with agas-impermeable barrier to prevent gas transfer with the surroundingatmosphere.

In any of the aforementioned methods, the secondary container may be asecond tray having an upper surface and a cavity surrounded by an upperrim and descending downward therefrom. The second tray may be made ofgas-impermeable material and the cavity is sized to receive the firsttray, and the gas-impermeable seal may be a gas-impermeable label scaledto the upper rim of the second tray. In one embodiment, the second traycomprises a double flanged upper rim, and further includes agas-permeable lid sealed to an inner flange and the gas-impermeablelabel scaled to an outer flange. Or, the secondary container may be apouch of gas-impermeable material including a gas-impermeable seal, andthe pouch may also include a gas-permeable seal outside of thegas-impermeable seal. Still further, the secondary container may beplaced within a further gas-impermeable pouch of gas-impermeablematerial having a gas-impermeable seal.

A further understanding of the nature and advantages of the presentinvention air set forth in the following description and claims,particularly when considered in conjunction with the accompanyingdrawings in which like parts bear like reference numerals.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be explained and other advantages and featureswill appear with reference to the accompanying schematic drawingswherein;

FIG. 1 is an exploded perspective view of an exemplary dry aortic tissueheart valve and a holder therefore, and FIG. 2 is an assembledperspective of the heart valve and holder;

FIG. 3 is a perspective view of a subassembly of the heart valve andholder coupled to a disc-shaped storage clip;

FIGS. 4 and 5 are exploded and assembled perspective views of the heartvalve/holder and clip subassembly positioned within a tower half of aclamshell member used to stabilize the heart valve during storage;

FIGS. 6A-6D are orthogonal views of the clam shell member;

FIG. 7 is a perspective view of the heart valve/holder and clipsubassembly positioned in the clam shell member with an upper halffolded closed over the lower half;

FIG. 8 illustrates the assembly of FIG. 7 placed within a cavity of astorage tray, and a gas-permeable lid for sealing over an upper surfaceof the tray;

FIGS. 9A-9C are orthogonal views of the storage tray;

FIG. 10 is a plan view of the underside of a gas-permeable lid forscaling over an upper surface of the storage tray;

FIG. 11 is a plan view of an upper surface of a pressure sensitive foillabel sized to cover storage trays disclosed herein and provide agas-impermeable barrier for long-term storage of heart valves;

FIG. 12 is an exploded perspective view of the aforementioned storagetroy and clamshell member on either side of an exemplary dry mitraltissue heart valve subassembly including a holder and protective cage;

FIG. 13 shows the mitral tissue heart valve subassembly seated withinthe cavity of the storage tray with the clamshell member positionedthereover to limit vertical movement of the subassembly in the cavity;

FIG. 14 shows an alternative disc-shaped insert prior to coupling to themitral tissue heart valve subassembly;

FIG. 15 shows the combination of the disc-shaped insert and mitraltissue heart valve subassembly seated within the cavity of the storagetray;

FIGS. 16A and 16B shows a gas-permeable lid positioned over and sealedto the storage tray having the initial heart valve subassembly therein;

FIG. 17A-17C are orthogonal views of a secondary storage tray sized toreceive the first storage tray;

FIG. 18 is a plan view of an alternative secondary storage tray sized toreceive the first storage tray and having double flanges;

FIGS. 19A-19C show several potential configurations of the relativeheights of the double flanges in the tray of FIG. 18;

FIG. 20 is a plan view of an exemplary secondary storage pouch sized toreceive the first storage tray;

FIG. 21 is a perspective view of the first storage tray positionedwithin the secondary storage pouch, shown transparent;

FIG. 22 is a perspective view of the first storage tray positionedwithin an alternative secondary storage pouch, shown transparent; and

FIG. 23 is a perspective view of the assembly of FIG. 22 positionedwithin a tertiary storage container in the form of a pouch, showntransparent.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention provides an improved double barrier packagingsystem for dry prosthetic bean valves that effectively stabilizes thevalve within a storage container without the need for a liquidpreservative, provides an efficient vehicle for gas sterilization, andprevents oxidation of the valve during long-term storage.

FIG. 1 is an exploded perspective view of on exemplary aortic tissueheart valve 20 and a holder 22 therefore. The present applicationdescribes packaging systems that are particularly suitable for storingdry prosthetic tissue heart valves, and as such do not require liquidcontainment. The exemplary aortic tissue heart valve 20 includes asewing ring 30 around an inflow end a plurality of upstanding commissureposts 32 circumferentially distributed around the valve and projectingin an outflow direction, and a plurality of flexible leaflets 34 thatprovide fluid occluding surfaces for the one-way valve. Although notshown, additional components of the heart valve 20 typically include aninner stem and/or wire form support structure that provide a structuralskeleton surrounding an inflow orifice and extending up the commissureposts 32. The inner components of the heart valve 20 may be made ofsuitable metal or plastic. An identification tag 35 secured to thesewing ring 30 with a length of suture provides a serial numberrepresentative of information regarding the type of bean valve 20 andother particularities about its manufacture, such as the date.

In the illustrated embodiment, the structural components of the heartvalve 20 support each flexible leaflet 34 along a cusp edge and alongtwo commissure edges. A free edge 40 of each leaflet 34 extends inwardtoward a central flow orifice and coapts, or mates, with the free edgesof the other leaflets, as shown. The most common configuration ofprosthetic aortic tissue heart valve has three flexible leaflets 34supported by three upstanding commissure posts 32, although differentconfigurations are conceivable.

Flexible leaflets 34 may be made front a variety of materials, thoughbioprosthetic tissue is considered to be most effective. The most commonbioprosthetic tissue is bovine pericardium, where the individualleaflets 34 are cut from pericardial sac of a cow. An exemplary drytissue heart valve that may be stored without need for liquidpreservatives in the packaging systems described herein may be obtainedfrom Edward Lifesciences of Irvine, Calif. One preferred tissuetreatment process includes applying a calcification mitigant such as acapping agent or an antioxidant to the tissue to specifically inhibitoxidation in dehydrated tissue and reduce in vivo calcification. In onemethod- tissue leaflets in assembled bioprosthetic heart valves arepretreated with an aldehyde capping agent prior to dehydration andsterilization. Exemplary processes are described in U.S. PatentApplication No. 20090164005 to Dove, et al., filed Jun. 25, 2009, thedisclosure of which is expressly incorporated herein by reference.

With reference still to FIG. 1, the exemplary holder 22 includes acentral hub structure 42 having a bore with internal threads 44, and aplurality of outwardly and downwardly angled legs 46. A narrow neckregion 48 separates the hub structure 42 and the upper end of the legs46. The legs 46 are arranged to contact and engage the valve sewing ring30 intermediate each pair of adjacent commissure posts 32, as seen inthe assembled perspective of FIG. 2. That is, the legs 46 contact thecusp regions of the heart valve 20. Although not shown, oneconfiguration for connecting the legs 46 to the sewing ring 30 includesattachment sutures that loop through the suture-permeable material ofthe sewing ring 30 and tie off on the holder 22. such as on one of thelegs 46. During implant, the surgeon manipulates a handle (not shown)screwed into the threaded bore 44 and advances the aortic heart valve 20into implant position at the aortic annulus. Once in position, andtypically after anchoring sutures have been deployed between the sewingring 30 and the surrounding native annulus, the surgeon severs theattachment sutures coupling the holder 22 to die valve 20, and removesthe holder and handle.

FIG. 3 is a perspective view of a subassembly of the aortic heart valve20 and holder 22 coupled to a disc-shaped storage clip 50. The dip 50 isdesirably planar and has a substantially circular outer periphery 52interrupted by a plurality of semi-circular notches 54 and a radial slot56. The clip 50 further includes a plurality of circular through holes58. The radial slot 56 terminates in a central circular aperture (notshown) sized approximately the same as the narrow neck region 48 of theholder 22. The width of the radial slot 56 is slightly smaller than theneck region 48, such that the holder 22 may be pushed inward along theslot and snapped into the central aperture, with the hub structure 42above the clip 50. As will be seen below, the clip 50 caps a cavity of astorage tray in which the heart valve is stored to stabilize the valvetherein.

FIGS. 4 and 5 illustrate a clamshell member 62 used to stabilize theheart valve 20 during storage. The subassembly of the valve 20, holder22, and clip 50 is shown in FIG. 4 exploded above a lower half 64 of dieclamshell member 62, and positioned within the lower half in FIG. 5. Theclamshell member 62 is desirably constructed of a transparent moldedmaterial, such as a polyethylene terepthalate copolymer (PETG).

The clamshell member 62 includes the lower half 64 hinged to an upperhalf 66. As seen also in FIGS. 6A-6C, clamshell member 62 is desirablymolded from clear plastic and the two halves connect at a living hinge68. The lower half 64 includes an annular rim 70 above and surrounding acircular aperture defined by a lower ledge 72 and having a finger tab 74extending away from the hinge 68. A plurality of separate moldedfeatures project inward from the annular rim 70 above the lower ledge72, including four clip supports 76 and un anti-rotation projection 78.As seen in FIG. 5, the generally circular clip 50 is sized to fit withinthe annular rim 70 and rest on the clip supports 76. The circumferentialwidth of the anti-rotation projection 78 permits it to fit closelywithin the radial slot 56 of the clip 50, thus preventing rotation ofthe clip in the clamshell member 62.

The clamshell member upper half 66 has an outer ledge 80 including afinger tab 82 extending away from the hinge 68. An inner generallycylindrical boss 84 fits within and mates with the inner surfacefeatures of the lower half annular rim 70. In particular, a series ofprojections 86 on the cylindrical boss 84 frictionally engage the innersurface of the lower half annular rim 70. The engagement of theprojections 86 with the inside of the rim 70 desirably provides anaudible and tactile click or snap upon closing the halves of theclamshell member 62. Prior to closing the clamshell member 62, theidentification tag 35 may be positioned on the circular clip 50 with theserial number facing upward for greater visibility and to prevent thetag from contacting and potentially damaging the heart valve 20 duringstorage. The final assembly of the valve/holder/clip in the closedclamshell member 62 is seen in FIG. 7. As an additional locking Feature,a downward projection 89 on the upper half 66 fits closely into themid-portion of the radial slot 56 of the clip 50, thus further limitingmovement of the clip in the clamshell member 62.

FIG. 8 then illustrates the assembly of FIG. 7 placed within a cavity 90of a storage tray 92, whereupon a gas-permeable lid 94 having an outerband of adhesive 95 seals over an upper surface 96 of the tray 92. FIGS.9A-9C are orthogonal views of the storage tray 92 illustrating a flat,horizontal outer rim 93 defining the tray upper surface 96, andsurrounding the cavity 90. The cavity 90 is formed by the inner contoursof a container portion 100 extending downwardly from the outer rim 98.The container portion 100 includes a stepped ledge 102 on an upper endand a lower trough 104. When the assembly of FIG. 7 is placed within thecavity 90, the clamshell member 62 rests on the stepped ledge 102 andthe heart valve 20 extends downward within the lower trough 104. Note inFIG. 6C, external features 105 on the lower half 64 of the clamshellmember 62 which frictionally engage the internal features 106 on thestepped ledge 102 of the storage tray 92. Engagement between thefeatures 105, 106 nominally retains the clamshell member 62 in thestorage tray 92, and prevents the clamshell member from falling out ifthe tray is inverted but presents minimal difficulty to a user removingthe clamshell member using the thumb tabs. Preferably, the features 105,106 engage with a snap or tactile feedback. Because the clamshell member62 secures the circular clip 50, which in turn secures the valve/holdercombination, the heart valve 20 is stably suspended within the cavity 90without touching the sides of the tray 92.

FIG. 10 shows the gas-permeable lid 94 that seals over the upper surface96 of the storage tray 92. More specifically, the outer rim 98 forms aflange to which the hand of adhesive 95 on the lid 94 may be adhered.Preferably, the lid 94 is closely dimensioned to the perimeter of theouter rim 98, and the hand of adhesive 95 is a pressure-seal or a heatseal adhesive to facilitate sealing under pressure and/or temperature.The material of the lid 94 is breathable, or gas-permeable, to providefor gas sterilization of the contents sealed within the tray 92, inparticular the dry tissue heart valve 20. One suitable gas-permeablematerial is a sheet of high-density polyethylene fibers, which isdifficult to tear but can easily be cut with scissors. The material ishighly breathable and water vapor and gasses can pass through thefibers, but not liquid water. For instance, various Tyvek materials fromDuPont may be used. Also, exemplary hot-melt adhesives used to securethe lid 94 to the tray 92 may be obtained from Perfecseal orOliver-Tolas, for example Such a material permits sterilization of thetray contents using Ethylene Oxide (ETO), which gradually passes throughthe lid 94 to the interior tray. The lid 94 presents a sterile barrierand prevents ingress of microorganisms. The tray 92 is desirably amolded material, such as a polyethylene terephthalate copolymer (PETG),that provides rigidity and protection from jostling and externalpressures. Various medical storage materials and packaging suitable forassembly of components of the present application are available fromcompanies such as DuPont, Perfecseal, Oliver-Tolas, and Mangar.

Ethylene oxide (ETO), also called oxirane, is the organic compound withthe formula C₂H₄O. It is commonly handled and shipped as a refrigeratedliquid. ETO is often used as sterilant because it kills bacteria (andtheir endospores) mold, and fungi. It is used to sterilize substancesthat would be damaged by high temperature techniques such aspasteurization or autoclaving. Ethylene oxide is widely used tosterilize the majority of medical supplies such as bandages, sutures,and surgical implements in a traditional chamber sterilization method,where a chamber has most of the oxygen removed (to prevent an explosion)and then is flooded with a mixture of ethylene oxide and other gasesthat are later aerated.

Certain features of the clamshell member 62 and storage tray 92facilitate gas sterilization, such as with ETO. Specifically, theclamshell member 62 provides a cap that limits vertical movement of theheart valve 20 in the tray cavity 90 while providing gas flow passagesfor gas How in and out of the cavity. Good flow of sterilization gas inand out of the cavity 90 facilitates complete and rapid sterilization ofthe tissue heart valve 20. First of all, the clamshell member 62 sits onthe stepped ledge 102, and a pair of diametrically opposed gas Howchannels 108 provide openings between the two elements for passage ofgas into the cavity 90. In addition, the engagement between the lowerand upper halves 64, 66 of the clamshell member 62 permits gas to flowtherethrough, around the upper end of the valve 20. More specifically,the circular clip 50 is supported by the four clip supports 76 above thelower ledge 72, allowing gas to How around the clip 50. Furthermore, theclip 50 includes large circular through holes 58 for direct gas flowtherethrough. In short, the stable yet discontinuous engagement of thepackaging elements permits good gas flow in and around the tissue heartvalve 20.

FIGS. 12-16 illustrates an alternative packaging system for mitral heartvalves. FIG. 12 is an exploded perspective view of the same storage tray92 and closed clamshell member 62 for aortic valve storage on eitherside of an exemplary mitral tissue heart valve subassembly 110,including a holder 112 and a protective cage 114. In contrast withaortic valves, the holder 112 for mitral valves attaches to the inflowend of the valve, typically to the sewing ring. Although not shown, theholder 112 includes engagement structure, such as attachment sutures,for removably attaching to the sewing ring of the mitral heart valve.

The holder 112 may take a number of forms, but typically includes anupper bore 116 having internal threads for attaching a delivery handle.One exemplary holder 112 that may be used is available as theTricentrix(r) holder system for use with the Carpenter-Edwards®PERIMOUNT Plus® mitral pericardial valve from Edwards Lifesciences ofIrvine, Calif. A shaft 118 of the holder 112 fits closely within aradial slot 120 in a clip member 122 attached to the upper end of theprotective cage 114. An identification tag 124 attached to the heartvalve sewing ring with a suture passes upward through the radial slot120. The holder 112 stabilizes the mitral heart valve in a fixedposition with the protective cage 114, which in turn prevents theoutflow end of the heart valve from advert contact with the inner wallsof tray 92, and later contact with external surfaces and instruments inthe operating room when the heart valve is removed for implantation.

FIG. 13 shows the mitral tissue heart valve subassembly 110 seatedwithin the cavity of the storage tray 92 with the clamshell member 62positioned thereover. When pressed down into the cavity of the storagetray 92, the clamshell member 62 acts as a cap on the cavity to limitvertical movement of the heart valve subassembly 110 therein. As before,frictional engagement between the external features 105 (FIGS. 6C and6D) on the lower half 64 of the clamshell member 62 and internalfeatures 106 on the stepped ledge 102 of the storage tray 92 retains theclamshell member as a cap over the heart valve subassembly 110.

As an alternative to the clamshell member 62, a disc-shaped insert 130may be used to provide a cap over the cavity storage tray 92, as seen inFIG. 14. The insert 130 defines a flat, generally planar disc havingfour outward protections 132 and a radial slot 134 open to an outerperiphery 136. The insert 130 is desirably formed of a suitable moldedplastic, such as a high-density polyethylene (HDPE). The slot 134 fitsclosely around a non-circular portion of the holder shaft 118 andincludes a narrowed region 140 that retains the shaft 118 at a closedcentral end of the slot 134. Once the insert 130 has been snapped ontothe heart valve subassembly 110, the combination may be lowered into thecavity of the storage tray 92, as seen in FIG. 15. The outwardprotections 132 snap under the internal features 106 on the steppedledge 102 of the storage tray 92 such that the insert 130 caps thecavity over the heart valve subassembly 110. Flow passages 142 alignwith the flow channels 108 provided in the storage tray 92 andfacilitate sterilizing gas flow between the insert 130 and tray. Asbefore, the identification tag 124 of the mitral heart valve may bepositioned over the top of the insert 130 so that the serial number isvisible from above without removing the heart valve subassembly 110 fromthe tray 92. Also, it should be noted that the insert 130 engages thetray 92 in a non-rotating manner, as does the insert slot 134 around thenon-circular holder shaft 118, which means that the valve holder 112 isheld stationary in the tray while a user couples a threaded handlethereto.

Once the mitral heart valve subassembly 110 has been positioned withinthe cavity of the storage tray 92, as in FIG. 15, and a cop such as theclamshell member 62 is snapped thereover, as in FIG. 16A, thegas-permeable lid 94 described above seals over an upper surface 96 ofthe tray 92, as in FIG. 16B. FIG. 15 shows the identification tag 124which is visible through the clear plastic of the clamshell member 62 inFIG. 16A. At this stage, the assembly, and in particular the mitralheart valve therein, can be subjected to gas sterilization, such as withETO.

The clamshell member 62 (or insert 130 for mitral valves) restrictsrotation of the aortic or mitral valve holders, and therefore providesan efficient way of attaching a threaded handle to the holder whilestill in the packaging.

One advantage of the packaging solutions described herein is a doublesterile barrier, wherein the inner and outer sterile containers allowfor gas sterilization, such as with ETO, and with a second seal theouter sterile container also provides a barrier between the product andthe surrounding atmosphere (e.g., oxygen) after sterilization. The innersterile container has been described above, and for both aortic andmitral heart valves results in the sealed storage tray 92 shown in FIG.16B. The sealed storage tray 92 is received within a secondary or outercontainer and the dual barrier assembly is then sterilized, so thatthere are redundant sterile barriers. Subsequently, the dual barrierassembly is sealed to prevent the outside air from reaching the heartvalve, thus preventing oxygenation and potentially reducingcalcification after implant In the exemplary packaging sequence, theinner and outer containers are first assembled together and each closedwith a gas-permeable barrier to form a dual barrier assembly which isgas-sterilized. Subsequently, the atmospheric barrier is added, such asby converting the outer container from being gas-permeable to beinggas-impermeable. However, if the entire process is done in sterileconditions, such as in a clean room environment, the inner container maybe closed and sterilized before being placed within the outer container,which is then closed and sterilized, in other words, there may be one ortwo sterilization steps prior to sealing the entire assembly against airingress.

The present application describes two different secondary barriers—one astorage tray similar to that described earlier, and the other a flexiblepouch. The secondary barrier protects and preserves the primary sterilebarrier package in a sterile environment and prevents oxygen fromreaching the heart valve within. A further outer shelf box may be usedto facilitate temperature monitoring during distribution and storage,and protect the delicate implant from distribution hazards such asshock, impact and extreme temperatures.

FIGS. 17A-17C are orthogonal views of a secondary or outer storage trayISO sued to receive the primary or inner storage tray 92. The secondarystorage tray 150 desirably mimics the shape of the primary storage tray92 such that the latter can be easily nest within a cavity 152 therein.As such, the storage tray 150 comprises an upper surface including aperipheral flange 154, and a container portion 156 extending downwardlytherefrom having a stepped ledge 158 on an upper end and a lower (rough160. The inner walls of the container portion 156 define the cavity 152,and closely receive the inner storage tray 92.

The outer storage tray 150 provides a rigid secondary sterile barrierthat protects and preserves the inner sterile barrier formed by theinner storage tray 92 and lid 94. Desirably, the outer storage tray 150is constructed of a molded material, such as a polyethyleneterephthalate copolymer (PETG). PETG is nominally gas-impermeable,though not entirely for the long-term storage needs described herein,perhaps years. The tray 150 instead may also be formed of a moldedmaterial that is gas-impermeable for the required time frame, thoughsuch materials may be somewhat more expensive than PETG. Once the sealedinner tray 92 is placed within the outer storage tray 150, agas-permeable lid (not shown, but similar to lid 94 of the inner tray92) seals against the flange 154 and permits sterilization gas (e.g.,ETO) to reach the spaces within both trays.

With reference back to FIG. 11, a gas-impermeable label 162 sized tocover the secondary storage tray 150 is shown. The label 162 is appliedover the sterilized tray 150, and sealed on top of the lid. Oncepressure adhered or heat sealed against the lid, the foil label 162provides a complete barrier to gas transfer. The label 162 preferablyincludes a layer of metal foil laminated to a layer of a gas-permeablematerial such as DuPont 1073B Tyvek, or more preferably is a singlelayer of foil. The label 162 may have information printed thereon aboutthe contents of the packaging, such us implant type, model,manufacturer, serial number, date of packaging, etc. A layer of pressuresensitive adhesive is provided to seal on top of the previously attachedlid.

In an alternative configuration, as seen in FIG. 18, an outer storagetray 180 features a cavity 182 for receiving an inner tray surrounded bya double flange with an outer flange 184 offset from an inner flange186. The inner flange 186 may first be sealed with a die-cut and heatseal adhesive coated gas-permeable lid (e.g., Tyvek) after placement ofthe inner sterile barrier package, enabling subsequent ETO sterilizationof the entire package, and in particular the space between the twosterile barriers. A gas-impermeable label such as a single layer of foilis then sealed to the outer flange 184.

FIGS. 19A-19C show several potential configurations of the relativeheights of the double flanges 184, 186 in the tray 180 of FIG. 18. In apreferred embodiment, both lids/labels applied to the flanges 184, 186are attached with beat sealed adhesive for better long-term integrity ofthe bond. Heat sealing is typically accomplished by pressing down on thelabel with a heated surface such as a flat platen. However, heat andpressure should be applied only once to each flange seal to avoidaffecting the seal integrity after formation, and a flat platen mayrequire implication. There are several ways to manage this.

In a first embodiment of FIG. 19A, the flanges 184, 186 are at the sameelevation. The gas-permeable lid or label is applied to the inner flange186 using a heated press shaped the same as the flange. Alternatively,an insert shaped like the flange 186 may be introduced between a flatheated platen and the tray. After ETO sterilization, the foil label isapplied to the outer flange 184 using a heated press shaped the same asthe flange, or an insert shaped like the outer flange between a flatheated platen and the tray.

FIG. 19B, the inner flange 186′ elevates about the outer flange 184. Inthis configuration, a flat heated platen may be used to apply heat to anadhesive-coated label for the inner seal, while the outer seal is formedusing a healed press shaped the same as the outer flange, or an insertshaped like the outer flange between a flat heated platen and the tray.

In FIG. 19C, the outer flange 184′ elevates about the inner flange 186.In this configuration, the inner seal is first formed using a heatedpress shaped the same as the inner flange, or an insert shaped like theinner flange between a flat heated platen and the tray. Subsequently, aflat heated platen may be used to apply heat to an adhesive-coated foillabel for the outer seal. The ability to use a flat heated platen for atleast one of the seals simplifies the assembly apparatus and procedure.

FIG. 20 is a plan view of an exemplary secondary storage pouch 190 sizedto receive the first storage tray 92, or inner sterile packaging. Thestorage pouch 190 includes a first gas-permeable portion 192 adjacent anopen end (to the left), and a second, larger gas-impermeable portion 194that is closed on the right end. The entire pouch 190 may be made of thegas-impermeable portion 194, except for a strip of the first portion 192on the upper layer, or the first portion 192 may form both the upper andlower layers of the pouch adjacent the open end. A first seal 196extends across the width of the open mouth of the pouch 190 in the areaof the first gas-permeable portion 192. The second seal 19-8 alsoextends across the width of the pouch 190 but fully within the secondgas-impermeable portion 194. During packaging, the first storage tray 92is placed within the pouch 190 and the first seal 196 closed, at whichtime the entire contents ore gas-sterilized. After the assembly issterile, the second seal 198 is closed to prevent any further contactbetween the interior of the pouch 190 and the surrounding atmosphere.

FIG. 21 is a perspective view of the first storage tray 92 sealed withthe lid 94 and positioned within the secondary storage pouch 190. Thetwo seals 196. 198 enable gas sterilization of the contents of the pouch190 prior to full sealing. More particularly, the first seal 196 may beclosed at which time the package may be subject to ETO sterilization.Because the first seal 196 extends across the gas-permeable firstportion 192, sterilizing gas can enter the interior of the pouch 190.After sterilization, second seal 198 is closed to prevent any furthergas, in particular oxygen, from entering the interior of the pouch 190.

The storage pouch 190 provides a flexible secondary sterile barrier, andmay be constructed of various materials or laminates having at least onegas-impermeable layer, with a foil/polyethylene fiber laminate beingpreferred. An inner layer of the foil material, such as available fromAmcor, may feature a laminate of Low Density Polyethylene (LDPE) tofacilitate seal under pressure and temperature. A tear notch on thepouch 190 may be provided for easy opening. With the second seal 198closed, the foil pouch 190 provides an oxygen and moisture barrier afterETO sterilization.

In an alternative configuration seen in FIG. 22, the secondary storagepouch 190 that receives the first storage tray 92 only includes a firstgas-permeable seal 200. In use, the first storage tray 92 is placedwithin the secondary storage pouch 190 and the seal 196 closed, at whichtime the entire contents are gas-sterilized. After the assembly issterile, the secondary storage pouch 190 and contents within are placedwithin a gas-impermeable tertiary container, such as pouch 204 in FIG.23, to prevent any further contact between the interior of the pouch 190and the surrounding atmosphere. The pouch 204 is desirably formed ofgas-impermeable material and has a gas-impermeable seal 206.

In general, therefore, a preferred method includes stabilizing a dryprosthetic heart valve within a first gas permeable container thatprovides some rigidity or protection from external damage. The firstgas-permeable container and contents are then placed in a secondarygas-permeable container, and the entire assembly subjected to gas-basedsterilization. Finally, the secondary container is sealed with agas-impermeable barrier, such as by placing it within a gas-impermeabletertiary container to prevent gas transfer with the surroundingatmosphere.

In addition to the various embodiments of the double sterile packagingdescribed above, the final packaging will typically include a shelf box,printed or unprimed, constructed of paperboard with a tamper-evidentcarton label as an indicator of the integrity of the package and placedin a foam box for insulation. Also, a temperature indicator formonitoring temperature during distribution and storage is attached tothe shelf box.

The packaging solutions disclosed herein facilitate access to tissueimplants, in particular prosthetic heart valves at the lime ofimplantation. The process for removing the aortic valve 20 of FIG. 1from its packaging will be described, though similar steps can be usedto remove the mitral heart valve of FIGS. 12-16. The first step isremoval of the outer or secondary sterile barrier, two embodiments ofwhich have been described. One or both sealed labels over the outer tray150, 180 are first detached, and the inner tray 92 scaled by the sterilelid 94 (seen in FIG. 16B) removed therefrom (alternatively, thetechnician tears open the pouch 190 of FIG. 21). At this stage, theinner sterile packaging may be transported to the immediate vicinity ofthe operation site without undue concern for the integrity of thepackage because of the relatively rigid inner tray 92 and sterile seal94.

Subsequently, the technician detaches the lid 94, exposing the assemblyseen in FIG. 8. The upper half 66 of the clamshell member 62 is liftedup from the lower half 64 to expose the generally circular clip 50 andvalve holder 22, as seen in FIG. 5. A delivery handle (not shown) canthen be threaded onto the holder, and the assembly of the valve 20,holder 22, and clip 50 removed from the clamshell member 62. Recall thatthe anti-rotation projection 78 of the clamshell member 62 engages theradial slot 56 of the clip 50 to prevent rotation of the clip in theclamshell member 62. This facilitates threading the handle onto theholder 22, such that the operation can be done with two hands. Finally,the clip 50 can easily be detached from the holder 22 by pulling it offlaterally, leaving the valve 20 on the end of the delivery handle readyform implant.

The packaging assemblies herein provide a number of distinctiveadvantages to manufacturers of dry prosthetic valves, which advantagesmay also be transferred to the storage of other tissue implants that canbe stored dry, such as dental implants, ligaments, vessel grafts, tissuepatches or scaffolds, etc. Indeed, certain aspects of the presentapplication can be utilized by makers of implants in general that arerequired to be stored in double sterile containers and which can besterilized using a gas such as ETO. One advantage of the packagingdescribed herein is that it contains and stabilizes the prosthetic beanvalve. Movement of the heart valve within the storage container isdetrimental as delicate tissue structures may be damaged if permitted tocontact the sides of the packaging.

Due to presence of a gas-permeable sterile barrier such as a TyvekHeader (breathable vent) the product can easily be ETO sterilized andaerated for acceptable levels of residuals. After appropriate aerationtime the outer container, or second barrier, can be scaled (e.g., foilto foil) to prevent long term oxidation of the dry tissue valve.

The ETO sterilization obviates traditional oven sterilization, thereforereducing the amount of energy spent in heating the packaged product inan oven for multiple days. Similarly, elimination of autoclaving of thejars and closures before packaging will reduce the energy consumptionrequired in the sterilization process.

As mentioned, the double sterile barrier allows for gas sterilization,such as with ETO, but also provides an oxygen barrier to the productafter sterilization. Consequently, the entire assembly can be reliablystored in oxygen-free conditions for extended periods of time, evenyears, yet the outer sterile container can be removed at the time of usewithout exposing the contents of the inner sterile container tocontaminants. The double layer of packaging enables sterile transfer ofthe inner package to the sterile operating field, and the inner packagecan even be temporarily stored for significant periods before theproduct is used. The new package design will be lighter in weight due tothe choice of materials (PETG/Tyvek and air vs. Polypropylene withglutaraldehyde) which will reduce the shipping costs for single unitshipments.

Indeed, the biggest advantage over existing “wet” heart valve packagedesigns is the elimination of storage and handling of liquidglutaraldchyde during the packaging and storage process, as well as theabsence of glutaraldehyde at the time of use. This reduces hazards tothe health of employees, customers, and patients, as well as theenvironment. Additionally, disposal of glutaraldehyde is bio-hazardousand therefore OSHA requires neutralization of the chemical beforedisposal or placement of appropriate controls for disposal. Due todecreased handling and critical storage requirements described herein,the packaging process is rendered less complex. The elimination ofglutaraldehyde will not require an increased level of insulation fromhigher temperatures as the dry tissue valve already has the capabilityto withstand temperatures as high as 55° C. Therefore this will likelyreduce the bulkiness of the design by reducing the size and insulationused for shipping the valve during summers and winters.

Current tissue valves available from Edwards Lifesciences are packagedin a 3.8 oz polypropylene jar/closure system with liquid glutaraldehyde.The presence of liquid glutaraldehyde requires the package design tomaintain a state of temperature that will not overheat or freeze thetissue valve. Therefore the current package is bulky and heavier due topresence of EPS (Expanded Polystyrene) foam end caps outside thesecondary package (shelf carton) which insulates from extremetemperature conditions. The polypropylene 3.8 oz jar/closure system withliquid glutaraldehyde, secondary package and foam insulation make thepackage design bulky and heavy resulting in increased space for storageand increased costs for shipping. The current single unit summer packweighs approximately 0.85 lbs where as the current single unit winterpack weighs approximately 1.85 lbs. The packages disclosed herein aresignificantly lighter.

While the invention has been described in its preferred embodiments, itis to be understood that the words which have been used are words ofdescription and not of limitation. Therefore, changes may be made withinthe appended claims without departing from the true scope of theinvention.

What is claimed is:
 1. A packaging assembly for storing a bioprostheticheart valve without a liquid preservative solution, the packagingassembly comprising: a holder comprising an engagement structureconfigured for removably attaching a bioprosthetic heart valve, theholder comprising a shaft; a cage comprising an upper end, the cageconfigured to at least partially enclose the bioprosthetic heart valve;and a storage tray comprising a cavity for housing the cage; an insertsized to provide a cap over the cavity of the storage tray, the insertcomprising a slot having a closed central end and an open outerperiphery, the shaft of the holder being non-rotatably retained at theclosed central end, wherein the insert defines a flat, generally planardisc comprising at least one of outward projections and flow passages;and wherein the packaging assembly does not comprise a liquidpreservative solution.
 2. The packaging assembly of claim 1, wherein theengagement structure of the holder comprises attachment suturesconfigured for removably attaching to a sewing ring of the heart valve.3. The packaging assembly of claim 1, wherein the holder comprises anupper bore having internal threads configured for attaching a deliveryhandle.
 4. The packaging assembly of claim 1, wherein the storage traycomprises flow channels.
 5. The packaging assembly of claim 1, whereinthe storage tray comprises a stepped ledge to suspend the cage withinthe cavity.
 6. The packaging assembly of claim 5, wherein the insertcomprises outward projections and the storage tray comprisescorresponding internal features and wherein the outward projectionsengage the internal features of the storage tray to limit rotationalmovement of the insert when positioned on the stepped ledge.
 7. Thepackaging assembly of claim 5, wherein the insert comprises flowpassages and the storage tray comprises flow channels and wherein theflow passages align with the flow channels when the insert is positionedon the stepped ledge.
 8. The packaging assembly of claim 1, wherein theinsert comprises both outward projections and flow passages.
 9. Thepackaging assembly of claim 1, further comprising a clip memberconfigured to be attached to the upper end of the cage, the clip membercomprising a radial slot for receiving the shaft of the holder.
 10. Thepackaging assembly of claim 1, further comprising a gas-permeable lidconfigured to seal an open end of the storage tray.